1. Field of the Invention
This invention relates to a mechanism for supplying sliver to the fiber resolving roller of an open end spinning device which supply mechanism is adjustable for adaptation to slivers having different average stable fiber lengths.
2. Prior Art
In open end spinning devices, fiber sliver is conventionally fed by a supply roller and a cooperating pressure member to a resolving roller. The resolving roller has needles, teeth or an otherwise roughened periphery for resolving sliver into individual fibers which are then fed to a fiber collection surface for spinning into thread or yarn. The present invention relates to the mechanism for supplying sliver to the resolving roller, and the drawings show such apparatus in relation to a fragmentary portion of a typical resolving roller. Representative fiber transport and spinning apparatus used with such a resolving roller is shown in U.S. Pat. No. 3,797,218.
Apparatus has been previously disclosed for altering the distance between the sliver supply device and the resolving roller by resetting or exchanging parts in order to adapt to slivers of different average staple fiber lengths. U.S. Pat. No. 3,439,488, West German patent application Publication No. 2 136 178). The prior devices which utilize an exchange of parts require partial dismantling of the resolving device housing in order to afford access to the parts to be exchanged. Such parts exchange is very time consuming and must be done at each spinning station of a multiple station spinning machine. Even those devices which can be reset without dismantling the machine housing require a great deal of time, and, as a rule, must be reset station by station. In modern spinning machines having a large number of spinning stations, such adjustments are inordinately time consuming.
West German patent application Publication (offenlegungsschrift) No. 2 036 007 shows a device with two clamping elements at different distances from a resolving roller. However, the clamping element closer to the resolving roller cannot be rendered inoperative to adjust the device for clamping long staple fiber solely at a distance from the resolving roller equal to the average staple length.
West German patent application Publications (Auslegeschrift) Nos. 1 099 409 and 1 160 764 show other types of fiber sliver supply devices. However, the devices include expensive and complicated gear units which must be provided at each spinning station making the devices impractical.